1. Field of the Invention
The present invention relates to a motor control circuit for a mirror device used in an electric door mirror device or the like for a vehicle.
2. Description of the Related Art
Among rearview door mirrors disposed at the side of a door panel in correspondence with a driver seat or a passenger seat in a vehicle, there is an electric door mirror device where the door mirror can be folded and stored by the driving force of a motor so that the mirror faces a substantial vehicle width-direction interior.
This type of electric door mirror device is ordinarily disposed with a folding/deploying switch disposed near the driver seat in the vehicle. Power is supplied from the battery of the vehicle to a folding/deploying motor via the switch and a control circuit of the motor (see Japanese Patent Application Laid-Open (JP-A) No. 8-142756).
In the electric door mirror device, the control circuit is configured to stop the motor when the mirror has been rotated to a fixed deployed position and a fixed folded position. As an example of such a control circuit, there is a configuration that detects a load applied to the motor and cuts off current flowing to the motor when a load of a predetermined value or greater has been applied to the motor.
That is, the mirror is rotated to the deployed position or the folded position and further rotation thereof is restricted. Thus, when the motor is locked, a lock current that is larger than an ordinary activation current flows to the motor. The control circuit has a configuration that cuts off the current flowing to the motor when the lock current has flowed to the motor.
Although a relay circuit is used for the control circuit of the configuration that detects the lock current and cuts off the current flowing to the motor, a relay circuit usually has drawbacks in that the circuit scale is large and the circuit configuration is complicated.